The Greatest One(GOne) Engine is a specialized to develop 3D FPS genre game. It provides full-set functionalities such as an indoor map terrain editor with BSP(Binary Search Partitioning), PVS(Potential Visible Set) rendering algorithm as well as a character editor tool with a skinning animation and automatic joint bounding generation system. Also, it provides a particle effect engine and tool, plus, Lua based script engine and flash UI system for current FPS game trends. This engine also defines GONE 3D model data with our own well-optimized data structure when they were exported from 3D Max. All generated data, manually processed with our tools, will be controlled with Lua script for a specific game scenario. Even though this engine was started without anything, it provides good quality of special effects such as shadow and various HLSL shader effects.